Field of the Invention
The invention relates to a rotor blade and to a method for producing a rotor blade.
Description of the Related Art
Rotor blades for wind power plants are of course well known in the prior art.
Disclosed in DE 10 2012 107 932 B4 is a rotor blade which consists of a fibre composite system. In this case, rotor blade half-shells are first of all produced and adhesively fastened to each other. For stabilising the rotor blade half-shell in the impact direction, that is to say perpendicularly to the pivoting direction, or rotor plane in which the rotor blade rotates, provision is made between the rotor blade half-shells for ribs which are adhesively fastened to the rotor blade half-shells via girders. Girders and ribs form a double-T beam in cross section. In rotor blades, provision is made on the rotor blade half-shells in each case for a main girder which extends in the main along the line of the largest profile heights. The oppositely disposed main girders are interconnected via a rib.
Also in conformance with the prior art is to provide in rotor blades for wind power plants girders consisting of fibres which in the main extend in the direction of the longitudinal direction of the rotor blade and are positioned directly along the trailing edge of the rotor blade. In this case, both half-shells, which are component parts of the rotor blade, have in each case a trailing-edge girder which in accordance with the prior art are then directly adhesively fastened to each other along the trailing edge.
A disadvantage to the known rotor blades is the fact that more material has to be used for forming the trailing-edge girder than would be necessary for meeting the strength requirements since this configuration according to the prior art has a very strong tendency towards buckling instability if the trailing edge of the rotor blade is subjected to pressure load. Therefore, additional layers of fibre pre-products have to be introduced in order to achieve the required safety against buckling. Since, however, the distance between the surface of the aerodynamic pressure side of the rotor blade and its aerodynamic suction side is small, the Steiner proportion, which each additional layer of fibre pre-product creates, is also low. Therefore, the effectiveness of additional layers of fibre pre-products in the trailing edge for increasing safety against buckling instabilities is very low and a very large additional number of layers of fibre pre-products is required, which makes the rotor blade unnecessarily expensive.